Cadillac STS-V

Cadillac STS-V Cadillac STS-V
First Drive Review

Cadillac is determined to make inroads into the luxury market that's been dominated by the Germans for the past 30 years. The Detroit brand has steadily been introducing strong new products over the past three years. And like the premium automakers in Germany, Cadillac has established a performance division to attract wealthy hot-bloods as well as enhance the appeal of the entire division.

The first of these hot-bloods was the Corvette-engined CTS- V that appeared last year. Now Cadillac has unveiled a hot-rodded version of the STS, the division's newest product. This STS- V eschews the pushrod Corvette V-8 in favor of the well-established 32-valve, four-cam Northstar V-8, one that is, for the first time, energized by a Roots-type supercharger.

Spinning at 2.1 times crankshaft speed, the supercharger, which displaces two liters of air with each revolution, creates 12.0 psi of boost in the intake system. The inevitable temperature rise produced by this compression is ameliorated by four Laminova cooling tubes with closely spaced fins within the intake manifold. This intercooling system has its own dedicated heat exchanger in the STS- V's nose.

The Northstar engine gets the expected changes and upgrades demanded by this supercharging. This includes increased cooling flow within a reinforced block, oil-cooled pistons with a reduced 9.0:1 compression ratio, stronger rods, and a bore reduction from 93 millimeters to 91, reducing displacement from 4.6 to 4.4 liters for improved fuel economy.

To make the most of the supercharger's forced feeding, the Northstar SC, as it's called, also gets a low-restriction intake and exhaust system and Extrude Hone exhaust ports (imagine a really thick and highly abrasive toothpaste forced through the ports to smooth any rough edges).

All of this adds up to 440 horsepower at 6400 rpm and 430 pound-feet of torque at 3600 rpm. That's a useful 120-hp improvement over the standard STS V-8, but it doesn't exactly set new standards for the class. The R versions of the Jaguar S-type and XJ have 390 ponies. The Audi RS 6 had 450 horses. The Mercedes E55 has 476 horsepower. And the upcoming BMW M5 will have 500.

Still, this is enough power to keep the STS- V competitive, especially as it is coupled to a brand-new six-speed automatic transmission, the GM 6L80. With a 6.00 ratio spread between first and sixth gears, this transmission should be able to fully exploit the blown engine's broad torque curve while delivering decent fuel economy. The transmission also provides for manual gear selection as well as Cadillac's excellent Performance Algorithm Shifting, which makes the transmission feel at home on tracks and winding roads.

To match the 38-percent power increase, the STS- V gets numerous chassis changes. The front and rear cradles are reinforced. The engine is lowered to provide clearance for the larger transmission. The front and rear springs and the anti-roll bars are stiffer by 10 to 20 percent, along with much stiffer compression damping in the monotube Sachs shock absorbers. Even the steering gear was changed to a slightly quicker ratio to improve responsiveness.

Larger tires? Of course. The front end is shod with 255/45R-18s on 8.5-inch, 10-spoke wheels, and the rear gets 275/40-19s on 9.5-inch rims. Pirelli Eufori run-flats are fitted because the larger sizes won't fit in the STS spare-tire well. Braking comes from the same large Brembos that are fitted to the CTS- V.

You'll be able to recognize the V-series version of the STS most readily from the front, where it is distinguished by larger upper and lower grilles fitted with stainless-steel wire-mesh inserts, a front fascia that is two inches lower, with a more aggressive splitter, and a power bulge in the hood. The rear fascia is also lower, and the rear spoiler is slightly higher than the standard one. Coupled with new rocker panels and some underbody changes, these mods reduce lift at the cost of an increase in drag coefficient from 0.32 to 0.33.

Inside, the STS- V gets a luxurious leather-wrapped instrument cluster, suede-like seat inserts, olive-ash burled-wood trim, and various accents. The look definitely works for us, but we won't get a chance to drive the car until late spring.

Although the addition of the supercharger, its associated hardware, and the upgraded chassis components bring the STS- V's weight up to about 4300 pounds, Cadillac promises a 0-to-60 sprint in less than five seconds and a top speed of 165 mph. That should put the STS- V in the hunt with the other luxo hot-rod sedans. Pricing hasn't been announced, either, but we expect the car will come in at about 75 grand, well under the prices of its German competitors. We definitely see a heavyweight comparison test in this car's future.